Rocky Roundup:

Target have Motormaster. I think they have one or two left. They also still have both Megatrons.

K-Mart have very little. What they do have is the second wave of RID deluxes (or whatever they're called) with Optimus and Drift.

Big W is also pretty thin on the ground. They don't even have second wave RID and mostly just have Hero Mashers. They do have a CW Skywarp which I nearly bought, but then didn't.

Millenium Comics & Collectables (small store in Northside Plaza) have the Combiner Hunters 3-pack from SDCC. It's $200 which is a bit extreme, though!